.\" Copyright (c) 1999 G. Adam Stanislav
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.\"
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.\"	libutf-8 v.1
.\"
.Dd April 1, 1999
.Dt SPUTU8 3
.Os
.Sh NAME
.Nm sputu8
.Nd utf-8 library function manual page
.Sh SYNOPSIS
.Fd #include <utf-8.h>
.Ft char *
.Fn sputu8 "unsigned int c" "char *buffer"
.Ft char *
.Fn utf8sputc "unsigned int c" "char *buffer"
.Sh DESCRIPTION
The
.Fn sputu8
function of utf-8 library converts a UTC-4 (31-bit Unicode) integer to a sequence 
of one or more characters representing its UTF-8 value, and writes the result to 
a buffer (character string). It appends a NUL at the end of the buffer, so it can be
processed as a standard C string.
.Pp
.Fn utf8sputc
is a macro which simply gives
.Fn sputu8
a name that may be more convenient to remember. It is defined in
.Aq Pa utf-8.h .
.Pp
The
.Fn sputu8
function and the 
.Fn utf8sputc
macro take two arguments:
.Fa c ,
the UTC-4 code, and
.Fa buffer ,
a pointer to a string of characters. The buffer must have at least seven
bytes available for writing: UTF-8 encodes Unicode into 1 - 6 characters, plus we 
need room for the terminating NUL.
.Sh RETURN VALUES
.Fn sputu8
returns the pointer to the terminating NUL. This allows you to append the next sequence 
of characters without having to determine where the string ends after each call to
.Fn sputu8 .
.Pp 
If 
.Fa buffer
is NULL, 
.Fn sputu8 
returns NULL. If
.Fa c
is not a valid UTC-4 code (i.e., its high bit is set), no conversion takes place, and 
.Fn sputu8 
just returns 
.Fa buffer .
.Sh SEE ALSO
.Xr libutf-8 3 ,
.Xr fgetu8 3 ,
.Xr fputu8 ,
.Xr sgetu8 3
.Rs
.%A F. Yergeau
.%T UTF-8, a transformation format of Unicode and ISO 10646
.%O RFC2044
.Re
.Rs
.%A D. Goldsmith, M. Davis
.%T Using Unicode with MIME
.%O RFC1641
.Re
.Sh STANDARDS
ISO 10646-1: 1993 (``Unicode''), RFC 2044: 1996 (``UTF-8''),
.St -ansiC .
.Sh DIAGNOSTICS
You should always compare the 
.Sx RETURN VALUES 
to 
.Fa buffer .
If they are NULL, no conversion took place. Otherwise, if they are identical, 
.Fa c 
was not a valid UTC-8 integer. Anything else indicates successful conversion.
.Sh AUTHORS
This
manual page was written by
.An G. Adam Stanislav Aq adam@whizkidtech.net .
.Sh BUGS
None known.